Science: Halt the brain drain: help the whale: A moral argument against whaling can be based on the mammals' intelligence, says Benjamin Mee

THE Norwegian Prime Minister, Gro Harlem Brundtland, was once the darling of the environmental movement, lauded for her work as chair of the UN World Commission on Environment and Development. Last month, however, one of Europe's biggest conservation bodies, the European Environmental Bureau, decided to take back the prize it had awarded her in 1989, in protest at Norway's resumption of whaling.

Earlier this year, the chief scientist at the International Whaling Commission resigned in protest at what he claimed was politically motivated rejection of the IWC's scientific findings. The majority of member governments of the IWC had rejected the idea that a new scientifically based species-management scheme could allow some whales to be hunted, without the danger of driving them into extinction.

Why does the hunting of whales continue to rouse passionate moral protest? Why, as Norwegians argue, should one not consider the whale in the same moral category as the cow? In fact, there is scientific evidence to underpin the moral argument that it is wrong for humans to hunt whales. This evidence is simple: whales (and their cousins, dolphins) are like humans, disproportionately brainy.

Brains use a lot of energy, and must pay their way in order to evolve. A species does not develop a large brain at random. The large, complicated brain that we need to function as humans is what separates us from other animals. Dolphins and whales also have large, complicated brains. They use them as much as we use ours.

In the early Seventies, the evolutionary biologist Harry Jerison developed the notion of the Encephalisation Quotient, or EQ. An animal's EQ score is a numerical value for the size of its brain compared with the size and complexity of its body. Other psychologists have since refined the way EQ is worked out to include the animal's metabolic rate in the equation.

A domestic cat has an EQ of 1. This means that it has exactly the right amount of brain tissue it needs to control its body, and makes it an excellent instinctive predator. Dogs have an EQ of about 1.8, which gives them a bit of spare brain to think with (though dog owners may feel this rating is over- generous). It is thought that this extra brain power evolved because dogs are social animals, with complicated hierarchies governed by rules. This has meant that natural selection has favoured the more wily.

It seems to be a rule that the more complicated an animal's social situation, the larger its EQ. Chimpanzees live in groups of about 50 members and score 3.0, whereas city-creating Homo sapiens weighs in with a mighty 7.4. We use this extra brain for abstract thought and what psychologists call 'higher functions'. Although we often live in cities, recent work by the anthropologist Robin Dunbar at University College London has shown that throughout our evolution the optimum group size for humans is just 150. Even now it is likely that we cannot maintain effective communications with more than 150 people at any one stage of our lives.

The bottlenose dolphin has an EQ of 5.6. It lives in close-knit communities of about 120 with up to 10 generations of relatives. About one-third of the dolphin's time is spent maintaining social ties within the group. Because they do not write anything down, all the information required to maintain these ties is stored in their heads. It is a cerebral society.

The dolphin has the largest EQ of the whale family, though there is still controversy about the exact way in which the quota is calculated. The brain of the killer whale, for instance, is five times the size of ours. Its body, although much bigger, may not be so complicated to control as ours, however. The EQ calculation is not subtle enough to take this into account. The blue whale, the largest animal ever to have lived, has the largest brain on the planet, although its EQ is not as high as that of the bottlenose dolphin.

The whale family is descended from a dog-like land mammal, which had an EQ of 1. Fossils show that for more than a million years after they adapted to the water, their EQ remained the same. Then it started to grow.

Yet, for animals with an EQ of 1, with a regular supply of food, like the progenitors of whales had, any offspring born with larger brains are at a disadvantage.

Their large brains are metabolically expensive to run, and provide no reproductive advantage. This is known as the 'evolutionary advantage of being stupid', and it particularly applies to water-dwelling mammals.

The neo-cortex, the thinking part of the brain, requires oxygen and glucose in enormous quantities, whatever the mental state. An aquatic mammal is at a disadvantage for hunting and evading predators if it has to surface frequently for air while also having to eat more to feed its large brain. Seals evolved in parallel with dolphins and whales, and also prey on small fish. They have an EQ of 1.

So if food supply is not the reason for the development of dolphin and whale brains, it must be social pressures. The complexity of dolphin

societies is such that it seems the stupid ones - those, say, only twice

as bright as the cleverest ape - are

incapable of learning the customs well enough to find a mate, pass

on their genes and thus bring down the EQ.

Brainpower is regarded as one of the distinguishing characteristics of Homo sapiens - and is often cited as one of the grounds for according humanity an elevated moral status. The disproportionate brain size of whales and dolphins entitles them to greater moral consideration than the Norwegian analogy with domestic cattle would allow.

Yet Norway has chosen to defy the International Whaling Commission ban on commercial whaling this year. It has embarked on a 'self-regulated' programme of hunting minke whales in Arctic waters. The reality of this is that hundreds of highly sentient creatures will be slaughtered, dying lingering and painful deaths from wounds inflicted by exploding harpoons. These often take several strikes to kill. It is a practice that should be ended at once.

(Photograph omitted)